The present invention relates to a hand planing tool with a rotating blade holder.
More particularly, it relates to a hand-operated planer which has a base body.
A hand-operated planer with a rotating blade holder is known from EP-A 48 304. Two thin hard-metal reversible planing blades of narrow width with a profiled back and smooth base are held on the blade holder. In so doing, each pressing plate engages in a groove on the back of each planing blade in a positively locking manner with an end edge having a nose-like profile. A cover shell is supported on each pressing plate and--indirectly--presses the planing blade into its work position on the blade holder. The hard-metal reversible planing blades have two cutting edges on opposite sides so that when one of the cutting edges wears out the second cutting edge can be used by reclamping the reversible planing blade on the blade holder.
The blade holder of the known hand-operated planer is not suitable for receiving high-speed steel reversible planing blades which, according to standards, are wider and higher than hard-metal reversible planing blades, since high-speed steel planing blades do not carry a slot on the back facing the cover shell, but rather on the opposite side, that is on their base surface.
Other blade holders or clamping devices are known for high-speed steel reversible planing blades. The planing blades can be held on these blade holders or clamping devices in a displaceable manner without pressing plates by adjusting screws which engage in the slot. However, these blade holders are not suitable for holding hard-metal planing blades.
Accordingly, known hand-operated planers can only be used with a single type of planing blade, i.e. either hard-metal reversible planing blades or high-speed steel reversible planing blades. This clearly limits the possibilities for using the known hand-operated planers.
The seemingly easiest way to use known hand-operated planers with different types of planing blades would be to adapt the construction of the high-speed steel reversible planing blade to that of the hard-metal reversible planing blade, e.g. by forming a slot in its back. The slot would have to have the same dimensions as the slot of the hard-metal reversible planing blade and there would be a substantial risk of confusing the two types of planing blades. Thus--although this would probably be prohibited by law because of the danger of confusion--a completely new type of high-speed steel reversible planing blade would have to be produced at a high cost for development. Its strength characteristics would be different since its shape differs from that of the original planing blade type and in general it could not be exchangeable with the known high-speed steel reversible planing blades. This would entail a high follow-up cost because planing blades are standardized and are manufactured in large quantities by a number of manufacturers for different types of machines. Thus, it would be necessary to stock the new type of planing blade separately.